Nearly 200,000 hip replacements are performed each year in the United States and the number is expected to continue to grow as the population ages. The usual reasons for hip replacement are osteoarthritis, rheumatoid arthritis and traumatic arthritis, all of which can cause pain and stiffness that limit mobility and the ability to perform daily living activities. Hip replacement surgery is usually performed when other measures (e.g., physical therapy, medications, and walking aids) are unable to overcome the chronic pain and disability associated with these conditions.
Various techniques are used by orthopedic surgeons to perform hip replacements. These include the following approaches: anterior, antero-lateral, anterior, posterior, and postero-lateral. The posterior and posteolateral approaches account for approximately 60% to 70% of hip replacement surgeries.
Traditional hip replacement surgery involves an open procedure and extensive surgical dissection. However, such procedures require a longer recovery period and rehabilitation time for the patient. The average hospital stay for open hip replacement procedures is 4-5 days, followed in most cases by extensive rehabilitation.
More recently, there has been considerable interest and research done in Minimally invasive Surgery (MIS), including the use of MIS procedures in connection with hip replacement surgery. In comparison with the traditional open surgical approach, MIS hip replacement surgeries involve fewer traumas to the muscles surrounding the hip joint. Specifically, fewer muscles that help to stabilize the hip joint are cut in MIS hip replacement surgeries, reducing the risk of dislocation of the hip surgery and speeding recovery. Patients spend less time in the hospital and return to normal life activities more quickly.
MIS approaches use smaller surgical fields, which require smaller instruments to perform the hip replacement procedures. One such instrument is a reamer spindle detachably connected to a surgical reamer. The surgical reamer is used to shape the bone of the acetabulum. However, reamer spindles have typically been straight with a handle in a fixed orientation. These prior art reamer spindles are not ideal for MIS approaches. The straight design and fixed handle orientation impedes the tool's ability to be used in small, tortuous spaces within the body, particularly of MIS procedures.
Accordingly, there is a need for an improved reamer spindle for use in MIS hip replacement surgical approaches. The present invention provides a reamer spindle with an offset reamer position and a handle that is able to be positioned in a multitude of orientations. These features of the reamer spindle of the present invention address previous shortcomings of previous reamer spindles, particularly for use in MIS procedures.